Transmitting apparatus.



L. DE FOREST.

TRANSMITTING APPARATUS.

APPLICATION nun 11113.24, 190a.

Patented Aug. 9, 1910.

UNITED STATES PATENT OFFICE.

LEE IDE FOREST, 'OF NEW/YORK, N. Y., ASSIGNOR TO THE RADIOTELEPHONE COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

mmsm'r'rme arrazaarus sp tliiflq l of Iiettera Patented Aug. 9, 1910.

Application filed 'August 24, 1908. Serial No. 449,949.

To all wi'wm' it may concern: v

Be it known t at I, Lnn on Forest, a

citizen "oi the United States, residing at New York, in the county of New York and State-oi; NewYork, have made a certain new and -usefnl liivention in Transmitting Aparatusyof which the following is a specication Tlis inv'entionrelates to systems for the transmission of signals or sounds through space telegraphically or telephonically, and more especially to such systems employing an electric-arc to produce high frequency vibratory currents.

The object of the invention is to iinprovc the eiliciency of the arccircuit.

' are consumed by'the are duringthe opera- A further object ist to maintain a uniform length of are thereby avoiding irregularities due to variations the arc length.

A further object as to prevent'the accumulation of carbon or other deposits upon the electrodes more rapidly than such electrodes steady are for generating high frequency oscillations. v

Other objects of the invention will appear more fully hereinafter. i

The invention consists in forming the arc' in a hydrocarbon ol;like vapor, as, for instance, in a vapor of alcohol eontaininga circuit, commonly known as the singing? hydrocarbon or similar element.

- The nventlon also consists in certain details of structure and arrangement for carry-w phone and telegraph systems employing, in

the transmitting apparatus, an energ zing R. arc clrcuit, and wh ch includes a condenser and means for producing an electric arc, I,

' have experienced great difficulty. by reason of irregularities resulting from variations to one hundred parts, more or laws. 9

in the length of the are, such variations causing instability and unsteadiness of the are and a consequent derangement of the riod or frequency of the oscillations. I

ave also found that-where atmospheres or vapors are employed, in which the arc is formed, for the purpose of attempting to secure stability and steadiness oi the are, the tendency is to cause an accumulation of depos ts upon the'arc electrodes, which deposits, continuing to accumulate, build up teats or protuberances. upon the electrode ends, thereby causing variations in the length of the arc, whichmsult in grave irregularities in the energizing circuit, throwing the same out of resonance with the other circuits of the transmitting and receiving systems.

It is among the special purposes of my present invention to avoid these and other objections attendant upon the practical operation of wireless transmitting systems as heretofore carried out and in. accordance with my invention I ose to provide means whereby deposits 0? carbon or like substance upon the carbon or other electrode is effected only in about the. proportion such electrode is consumed by the arc.

I also propose, in accordance with the principles of my invention, to provide means for insuring a. steady and uniform supply of the vapor or atmosphere to the are.

In carrying out my invention-in one form of practical application thereof, I form the arc in'an atmosphere of alcohol. or alcohol vapor 'employin 'for the purpose an alcohol con taining a hy rocarbon in sufficient amount only to supply a carbon or other deposit on the carbon electrode in proportion or substantially theprop'ort-ion in which the carbon electrode consumed by the are. -I have found that denatured alcohol is eliicient for my purposes, but other alcohols may be used when mixed with some suitablehydrocarbon in the proper proportions, as, for instance, 1

alcohol containing approxlmately ten parts, more or less, of methyl alcohol or instijylene pure or ethyl 95% alcohol, the essential being; that 'sutlicient carbon contaimn' jclement be mixed with the alcohol to pro not. on-cause a depositof carbon upon the carbon arp electrode to substantially equal or approximate the .consumption ofthe electrode by the are. Unless this result is accomplished the arc is rendered unsteady and unstable, and the length of the arc is constantly decreasing or varying, thereby rendering the apparatus unsuited for use in wireless telephony, and very ineficient for use in Wireless telegraphy. -My invention may be carried out practicell in many specifically different Ways, and

wit many specificull diii'erent arrangements of o. pcmtus. hile, therefore, I will now descri e one form and arrangement for accomplishing the desired objects my inycntion, in its broadest scope is not to be limited or restricted. to the specific details shown and hereinafter described.

'In the drawing reference si 1, desig netes'e source of electromotive orce, in this instance it direct current generator, 2, is an antenus or serial, 3 an earth connection for the outcome, 4 a condenser, 5, 6, the arc elec trodes, and 7, an'inductance or autotransformer. These various parts may have the usual or any Well-known relative arrange ment and relation. In the form shown the arc electrodes are included directly in circuitwith the source of electromotivo force, .ahd also in circuit with the condenser and .30 the primary of the induction coil or autotransformer, the secondary of the induction coil being included in circuit with the antonne and its earth connection.

The electrodes 5, 6, are errsn ed to extend E into a tubular chimney .8, and f i'om opposite directions, so that the arc is formed between the proximate ends of the electrodes within the chimney. This chimney is carried upon the neck 9, of a. tank or vessel 10,

0 designed to contain the carbon containing alcohol. A wick l1,. .is laced within this Vessel and one end of suc Wick extends up intothc neck 8, and into proximity with the arc electrodes. The carbon containing mlX- 5 ture is drawn up the Wick by the heat of the arc and is vaporized in the region of the are thereby forming'the desired atmosphere or vapor envelop for the are.

It is exceedingly desirable that the supply of vapor or atmosphere be maintained as steady and uniform as possible to the end that irregularities and variations in the arc may be avoided, and so as to attain the very best results. In order to accomplish this result I propose to feed the vessel 10, with the alcohol, or alcohol mixture, from u reservoir 12, which is placed at a higher ievel than the vessel 10, and connected thereto through u feed pipe'lil, which, if desired to and g'irei'erubly, connects to the bottom of the reservoir or vessel 10, as shown. Astopcoclr 14, in the feed pipe may serve to control the flow of alcohol mixture from the reservoir or supply tunlrlZ, to the vessel 10.

If desired, the vessel 10, may be sup lied to with a gage -gloss 15, thereby ens ling. the alcohol to emaintsined at a. constant uniform level in the vemcl 10.

Having now set forth the object and nature of my invention and a con'structionend '70 arrangement as an illustrative embodiment thereof, and having described such con-v struction and arrangement, its purpose, function and mode of operation, what I claim as new and useful, and of m own 75. invention, and desire to secure by etters Patent is:-

1. In a. transmitting ap aratus, a circuit including a condenser on meansfor producing an electric arc, in combination with means for maintaining an atmosphere of denatured alcohol vapor about said are.

2. In a. transmitting apparatus, and in combination with asinging arc circuit, of meansfor maintsinin mosphere or vapor of enutured alcohol.

3. The combmation'with means for developing electromagnetic waves includingarc electrodes between which an arc is formed, of means for supplying carbon to I the electrodes in substantially the proportion in which the electrodes are consumed by the are.

4. The combination with means; fordevelopin electromagnetic waves including '95 electro'cs between which an arc is formed and a chimney inclosin the same, of means for maintaining a dra. of curb containing vapor through the chimney 5. The combination with means 1'0] do veloping electromagnetic waves in ird electrodes between which an arc and a chimney inclosing the sum for maintaining a draft of vapo of, containing alcohol through the e lane 6. The combination. with means; veloping electromagnetic waves incl electrodes between which an etc of means for maintaining theirs, of a mixture of ethyl alcohol on m alcohol,

7. The combination withfina o veloping electromagnetic waves includmg arc electrodes, a. chimney into which the electrodes extend, a tankhovingul neck to '115 support the chimney, a wick contained in the tank and extending into the neck and means for supplying u-vapor producing material to the wick. i

8. The combinatiouwith means for (loveloping electrormagneti'c Waves including arc electrodes, a chimney into which, the electrodes extend, a tank carryiugthe chimney, a wick. arran ed inthe tank, and a reservoir supports inelevated position relative to the tank and communicating therewith. I

9. The combination with'means for de the arc in an put- 85 v vcloping electro-magnetic' waves including my hand in the presence of the sulmribing arc electrodes, of means for enveloping the \vltnesses, on this 15th clay of Angmi 5)., w arc in an atmosphere produced from a mix- 1908. ture of pure or ethyl alcohol and methyl IFE FUPPJV alcohol in about the proportion of ten parts of the methyl alcohol to one hundred parts Witnesses: of the ethyl alcohol. E. M. Tnmfis,

In testimony whereof Ihave hereunto set S. E. DARBY. 

